1. Field of the Invention
The present invention relates to systems and methods for examining biological material. In particular, the invention relates to improved optical readers or scanners for detecting emissions from biological probe arrays having small features that may be arranged in high densities on the arrays.
2. Related Art
Synthesized nucleic acid probe arrays, such as Affymetrix GeneChip® probe arrays, and spotted probe arrays, have been used to generate unprecedented amounts of information about biological systems. For example, the GeneChip® Human Genome U133 Plus 2.0 Array available from Affymetrix, Inc. of Santa Clara, Calif., is comprised of one microarray containing 1,300,000 oligonucleotide features covering more than 47,000 transcripts and variants that include 38,500 well characterized human genes. Analysis of expression data from such microarrays may lead to the development of new drugs and new diagnostic tools.